Process for the destructive distillation of wood.



B. R. & M. J. LYSTER. THE DESTRUCTIVE DISTILLATiON 0F WOOD. APPLICATION FILED DEC. n, r913.

' PROCESS IFOIR Patented Oct. 19, 1915.

richer in methane (CI-L),

UNITED sTAr sfATENT curios.

BENTON R; LYS IER AND MORTON J. LYSTER, OF WHITEFIELD, NEW HAMPSHIRE.

'PROOESSFOR THE DESTRUCTIVE DISTILLATION OF WOOD.-

Application filed December 11, 1913.

To all 701mm it may concern Be it known that we, BENTON R. LYSTER and MoRroN J. Lrsrnn, citizens of the United States, residing at lVhitefield, in the county of Coos and State of New Hampshire, have invented new and useful. Improvements in Processes for the Destructive Distillation of \Vood, of which'the following is a specification.

In the destructive distillation of wood for the purpose of manufacturing methyl'alcohol, acetate of lime, charcoal, etc.,in iron or steel retorts or ovens, it is well known that there are gases evolved'that do not condense and that these gases are usually returned to the oven fire-box or to fire-box under boilers and burned. carbonic acid ((10,), carbonic oxid (CO) methane (GIL), hydrogen .(H), etc. In the early stages of an operation, a gas rich in carbonic acid ((30 and carbonic oxid (CO) is obtained. Later, as the heat is raised in the ovens or'retorts, less carbonic acid (CO and carbonic oxid (C0) are thrown off, and the gases now evolved are hydrogen (H), and acetylene '(O H,), ethylene (C,H,), etc.

Our method. broadly, contemplates utilizing part or all of the incondensable gases formed during one stage or period of the operation and using them at another stage or period of the operation in a novel and desirable manner, as hereinafter more particularly described; and we have discovered, by practical application of our method, that our method effects a marked increase in the yield of methyl alcohol (CPLO), acetic acid (CJLO and a tar rich in guaiacol In the accompanying drawing, we have illustrated, as an example, a form of apparatus capable of carrying out the method of our invention; and, while our invention may be practised by other apparatus, such as storing the gases in a gasometer and returning them to the ovens as desired, that given is preferred as being the simplest and most practicable.

In this drawing? Figure l is a top plan view, partly in section, of the preferred form of our apparatus; Fig. 2 is an end elevation of the apparatus; Fig. 3 is a fragmentary detail view of one of the retorts.

Referring now in detail to the drawing: A, B, C, I), designate a battery of retorts or ovens, usually arranged in, pairs,as shown.

Specification of Letters Patent.

These incondensable gases are ()vens C and D Patented Oct. 19, 1915. Serial No. 806,061.

The retorts are in communication, by suitable connections 2, 2, 2, 2, with suitable condensers 3, 3, 3, 3, which are provided with outlets 4, emptying into a common conductor 5, which, in turn,. ay discharge into a suitable holder 6. Rising from each of the outlets 4 is a vertical pipe 7. The pipes 7 are in communication with a common horizontal pipe 8.

Leading from the pipe 8 are two pipes 9, 9, which are disposed between the two pairs of retorts A, B, C, and D, asshown. Carried bythe pipe 8, between the points of junction therewith of the pipes 9, 9, is a 'alve 10. The free extremities or terminals of the pipes 9, 9 communicate with the retorts A, B, C and I). e arrangement is such that the pipes 9, 9 are crossed, one of said pipes, on one side .of the valve 10, communicating with the retorts on the opposite side of the valve, and vice versa in respect to the other pipe 9; as clearly shown in the drawing.

- Preferably, a steam-jet nozzle 11, in communication with each pipe 9, is utilized, to accelerate the flow 9 into the retorts.

In the operation of our apparatiis, to carry out the process, constituting our invention, all of the ovens or retorts are charged with wood in the usual manner; but, contrary to the usual manner, the ovens or retort-s are not all run off at the same time, as for example, in a four oven plant, ovens numbered and B are charged with wood and the usual firing under these ovens is applied.

are charged with woodsame as A and B but from twelve to eighteen hours later than ovensA and B, and fired in usual way.

If a gas holder or gasometer is used to store the incondensible gases, the retorts or ovens may be charged with wood and fired off together and at the same time.

lVith an apparatus such as illustrated the operation of our invention is carried on as follows:The incondensable gases coming from the ovens last charged with wood are conveyed through proper pipes into the ovens charged with wood twelve to eighteen hours previously, 01', the incondensable gases coming from the ovens first wood are conveyed into the ovens which were charged from twelve to eighteen hours later, all ovens being fired as usual; The purpose of the foregoing is to bring in contact in a charged with of gas through the pipes heated oven the lncondensable gases evolved in ovens dunngthe first half of their op.

eration with the gases or vapors produced or formed in other ovens during the latter part of their operation. The gases, ensuing upon the process of reduction, pass into the condensers 3, 3 (to the left in Fig. 1), communi- P conductor 5.

-ever, pass up the pipes 7, that portion of the pipe ,side of the valve 10, in

'' rich in oxygen,

' effect, complementary later stage or stages,

' heated by external eating-with the corresponding pair of retorts; in these condensers, the condensable vapors are condensed, and the liquor flows through the outlets 4 into the trough or The uncondensed vapors,'how- 7, thence through 8 to the. left hand Fig.1, thence to the pipe 9 (that farthest to the left in Fig. 1), to the retorts or ovens with gases in these retorts or ovens and valuable products are formed.

.It appears that the non-'condensable gases, evolved in the earlier stage or stages .of destructive distillation, are, in to the non-condensable gases, deficient'in oxygen, produced in the and that, under the conditions obtaining in the retort, these constituents combine to produce additional amounts of the desired products, particuwe conduct the non-condensable gases from the freshly-charged ovens into the ovens that have been operating on their charge preferablyfor at least twelve hours; and we continue such introduction of said non-condenjsable gases, as aforesaid, to the end of the carbonizing period, which is from twenty-four to thirty-six hours in duration. It will thus be seen uncondensed gases into an oven or ovens in the latter part of their run. When the old charge is off and earlier wood isput into the ovens, of course the'gases coming from this fresh charge will then be piped over into the ovens that have previously sent their gases into the freshly-charged ovens, thereby supplying the saidovens to which said gases are piped with fresh gases during the latter the operation, process, into all the other ovens which are being run on the last twelve or fifteen hours period of operation,

(on the right-hand side of Fig. 1), Where they are combined the operation will be continuedthat we put the fresh,

part of their for example, all the non-oondensable vapors or gases thrown'off from the ovens, during the first twelve hours, or fifteen hours, of are to be introduced, by our of their charge.

The gist of our invention resides, broadly,

-in the admission of non-condensable gases or vapors, of predetermined character, such as are evolved from retorts at one stage or period of their operation, to'retorts at'a different and also predetermined stage or the gases and stages selected being, in effect, complementary with respect to the formation of additional amounts of alcohol and acetic acid.

Having thus fully described our invention,

What we'claim as new and desire to secure by Letters Patent of the United States, is:

1. The method of conducting destructive distillation of wood, which comprises distil? ling the charges in retorts by external heat, and introducing non-condensable gases relatively rich in oxids of carbon,.produced by one'retort or set of retorts during. a relatively early stage of distillation, into a retort or set of retorts during the progress therein of a relatively later stage of distillation which would ordinarily be characterized by the production of non-condensable 'gasesrelatively rich in hydrocarbons, where-- by additional amounts of the desired prodnets are formed.

'2. The method of conducting destructive operation. In other words,

distillation of wood, which comprises introducing charges into a plurality of retorts and externally firing the several retorts so as to effect destructive distillation of the charges, operations being so conducted that the different retorts or setsof retorts are a substantial stage apart in the distilling process, and introducing into each retort or set of retorts, after the termination of an early stage of distillation therein and during the progress of a further stage, non-condensable gases given off by another retort or' set of retorts then in an early whereby additional amounts of products are formed.

In testimony whereof, we have hereunto set our hands in presence of two subscribing witnesses. I

the desired -BENTOl T R. LYSTER. MORTON J LYSTER. Witnesses: I r

C. N. WHITE, A. G. HOWARD.

stage of their run, 

